Background references include the following references, all of which are hereby incorporated in their entireties into the present patent application:                1. “Electrical and Thermal Modeling of Railguns”, Kerrisk, Jerry F., IEEE Transactions on Magnetics, Vol. Mag-20, No. 2, March 1984, pp. 399-402, U.S.A.        2. “Loss of Propulsive Force in Railguns with Laminated Containment”, Parker, Jerald V., and Levinson, Scott, IEEE Transactions on Magnetics, Vol. 35, No. 1, January 1999, U.S.A.        3. “Eddy Current Effects in the Laminated Containment Structure of Railguns”, Landen, Dwight and Satapathy, Sikhanda, IEEE Transactions on Magnetics, Vol. 43, No. 1, January 2007, U.S.A.        4. “Phenomenological Electromagnetic Modeling of Laminated-Containment Launchers”, Mallick, John, IEEE Transactions on Magnetics, Vol. 43, No. 1, January 2007, U.S.A.        5. “Enhancement of the Compressive Strength of Kevlar-29/Epoxy Resin Unidirectional Composites”, D'Aloia et. al, High Performance Polymers, Vol. 20, pp. 357-364, June 2008, first published December 11, 2007.        6. Quickfield Version 5.7, Finite Analysis System, Tera Analysis, Ltd., Svendborg, Denmark, 2009, http://quickfield.com (last downloaded Nov. 1, 2010)        
Kerrisk [Reference 1] taught that a gun barrel electrically conductive along the major gun axis could not be brought into close proximity to the current carrying rails of a railgun without significantly reducing rail inductance. Given the barrel geometry, which was fully enclosing of the rails, and the other boundary conditions used, the conclusions arrived at were correct.
However, consider the following. The gas law is represented by a scalar equation and hot gas produces an isotropic pressure. Consequentially, the barrel for a standard gun must be everywhere continuous in theta and z to prevent gas escape and force loss on the back projectile surface. On the other hand, the magnetic field is defined by Maxwell's equations, and the magnetic field is a vector quantity. It follows that the magnetic pressure is a vector quantity. The barrel design for a magnetic gun can take advantage of this fundamental difference between these two cases. It is not necessarily required that the barrel be continuous in theta and z for full magnetic pressure containment and for the magnetic pressure to be properly applied to the back armature surface. That is, the barrel need not be fully enclosing of the rails.
If the electrically conducting gun barrel: (1) is split open top and bottom from the breech to the muzzle, and (2) the two new barrel sections make contact with each other only at the gun base (i.e., the gun breech), the condition for completing the image current circuit in the armature region can no longer occur, as discussed by Kerrisk [Reference 1]. This represents the case where each of the two independent barrel sections is mechanically anchored to the gun base with direct metal-to-metal mechanical contact. Therefore, the barrel sections are electrically connected to each other at the base. However, the two barrel sections remain electrically isolated from each other everywhere else along the length of the gun barrel. This new barrel configuration is described herein.